Super VF3 tool change problem

[Energy Rebel]

Hello.
I've been asked to look at someone else's machine on my upcoming vacation. (I know, right?)
Anyway, here's all the info I got. Any suggestions, ideas, previous similar symptoms you've had - all appreciated because I'll be flying blind, I think.

This is an intermittent problem - maybe a few times a day, maybe in a week.
The spindle will orient correctly (so I'm told), the tool goes in fine, arm retracts, but then - the spindle turns slightly before the tool is fully up in spindle resulting in the drawbar holding it but it's now actually .100 or so too low due to the dogs not being lined up with the notches in the tool holder.

In other words, it seems like the tool change takes too long and the spindle begins turning before it's fully engaged.

I know it doesn't make much sense and I won't be able to verify a lot of the obvious before I get there Monday, but if anyone has had something that sounded similar in the past, it might save me a lot of time.

I talked to my local HAAS dealer today and he thought it might be the air solenoid acting up. The spindle doesn't have the old style shot pin orientation - it's all electronic now, so it could also be the electronic brake acting up.

And of course I'll have to check, chips, retention knobs, "finger" alignment, encoder cables and pulleys etc.

Anything other ideas?

Thanks in advance.

PS.
I've got some service experience on various brands - mostly self taught - but feel free to talk "tech" to me.

[HuFlungDung]

I presume that there is still an encoder up in the head there somewhere? Could it have a loose setscrew in a coupling or drive pulley to the encoder? Loose setscrews might be most likely to be intermittent in effect. I suspect the vector drive still relies on the encoder to maintain the stopped position of the spindle motor.

[Energy Rebel]

Yeah, that's one of the first things I'm going to look at. I've heard about the set screw on that pulley needing a 2nd one to lock it down.
The thing is, if it slipped enough to jump a tooth on the encoder pulley, it should be "off" every time after that.
If it's just slipping a little, maybe it would act like he's describing.
I just wanted to have more than one "trick" in my bag so I don't get the "It's started doing it again" call.

Thanks.

[HuFlungDung]

I don't know anything about debug mode, but if you do, maybe there is a way to get in there and view the spindle encoder position in real time and maybe you can figure out something from that.

[Energy Rebel]

Originally Posted by HuFlungDung I don't know anything about debug mode, but if you do, maybe there is a way to get in there and view the spindle encoder position in real time and maybe you can figure out something from that.

10-4.
I saw something about that in another thread and I'm hoping to talk to a HAAS tech when I get there and see if he can talk me thru it.
Diagnosing all the feedbacks in the computer while it's running will sure help.

BTW, I recognize your handle from you know where.
Nice to see ya. lol

[Haas__man]

I would say it is unlikely to be a belt/encoder/set screw problem. As you said in an earlier thread if one of these were a problem then orientation would be all over and the machine would hardly ever tool change properly.
The probelm could possibly be parameter related. Try orientating the spindle - now look at the spindle dogs and see if they are ascilating backwards and forwards. If so this could be causing your problem and can be adjusted using parameters 192 - Mag current or 188 or 193.
Also it may not be an orientation problem, it could be a problem with the position of the arm ( which is not an easy task if you have not done it before), or the mechanical lock system on the arm that prevents the tools from moving during a tool change could be malfunctioning. Using tool change recover, put the arm in the down position. Now near the center of the hub you will see two silver buttons, they should press down and then spring back up. When they are pressed down the tools can be removed from the arm. Make sure that the buttons spring back up ok or lubricate if neccasary.
One last thing, make sure that orientation is set correctly, and also check that the spiundle dogs and the dogs on the arm are not worn.
Hope this helps.

[Energy Rebel]

Well thanks to all, very much appreciated.
I suspected an air pressure/solenoid problem from the beginning, and after making adjustment, it seems to have worked- so far anyway, LOL
Thanks again

[Ashish B]

Hi

I am undergoing through the same problem.

==> After M19, my spindle orients properly but it jerks suddenly

==> Also if i rotate the Clamped spindle by hand it moves 2 to 3 degrees & again tries to restore its original position.


I think i should increase the clamping force on spindle after M19 - BUT

1. Is it possible to change through Parameter Setting ?
2. What is the recommeded force ?
3. What is maximum force & need to know if any consequences are there if the force exceeds maximum limit ?

Thanks...Need Help Urgently.

Ash

Also attaching a parameter dictionary for easy refrence.